Activate PEP 582 by writing env var into WinReg

Close #191

README.md

@@ -108,7 +108,7 @@ if __name__ == '__main__':
     app.run()
 ```
 
-Set environment variable `eval $(pdm --pep582)`. Now you can run the app directly with your familiar **Python interpreter**:
+If you are a Bash user, set the environment variable by `eval $(pdm --pep582)`. Now you can run the app directly with your familiar **Python interpreter**:
 
 ```bash
 $ python /home/frostming/workspace/flask_app/app.py
@@ -119,7 +119,7 @@ $ python /home/frostming/workspace/flask_app/app.py
 
 Ta-da! You are running an app with its dependencies installed in an isolated place, while no virtualenv is involved.
 
-You can also preserve the setting by appending the output of `pdm --pep582` to the end of `.bash_profile`.
+For Windows users, please refer to [the doc](https://pdm.fming.dev/#enable-pep-582-globally) about how to make it work.
 
 If you are curious about how this works, check [this doc section](https://pdm.fming.dev/project/#how-we-make-pep-582-packages-available-to-the-python-interpreter) for some explanation.
 

README_zh.md

@@ -103,7 +103,7 @@ if __name__ == '__main__':
     app.run()
 ```
 
-设置环境变量`eval $(pdm --pep582)`，现在你可以用你最熟悉的 **Python 解释器** 运行脚本：
+如果你使用的是 Bash，可以通过执行`eval $(pdm --pep582)`设置环境变量，现在你可以用你最熟悉的 **Python 解释器** 运行脚本了：
 
 ```bash
 $ python /home/frostming/workspace/flask_app/app.py
@@ -113,7 +113,8 @@ $ python /home/frostming/workspace/flask_app/app.py
 ```
 
 当当当当！你已经把应用运行起来了，而它的依赖全被安装在一个项目独立的文件夹下，而我们完全没有创建虚拟环境。
-你如果希望自动启用此特性，将`pdm --pep582`的输出贴到你的`.bash_profile`后面即可。
+
+如果你是 Windows 用户，请参考[文档](https://pdm.fming.dev/#enable-pep-582-globally)获取设置的方法。
 
 如果你好奇这是如何实现的，可以查看[文档](https://pdm.fming.dev/project/#how-we-make-pep-582-packages-available-to-the-python-interpreter)，有一个简短的解释。
 

docs/docs/index.md

@@ -47,7 +47,16 @@ $ pip install --user pdm
 ### Enable PEP 582 globally
 
 To make the Python interpreters aware of PEP 582 packages, one need to add the `pdm/pep582/sitecustomize.py`
-to the Python library search path. The command can be produced by `pdm --pep582 [<SHELL>]` and if `<SHELL>`
+to the Python library search path.
+
+#### For Windows users
+
+One just needs to execute `pdm --pep582`, then environment variable will be changed automatically. Don't forget
+to restart the terminal session to take effect.
+
+#### For Mac and Linux users
+
+The command to change the environment variables can be produced by `pdm --pep582 [<SHELL>]`. If `<SHELL>`
 isn't given, PDM will pick one based on some guesses.
 
 You may want to write a line in your `.bash_profile`(or similar profiles) to make it effective when login.
@@ -57,6 +66,8 @@ For example, in bash you can do this:
 $ pdm --pep582 >> ~/.bash_profile
 ```
 
+Once again, Don't forget to restart the terminal session to take effect.
+
 **This setup may become the default in the future.**
 
 ### Use the docker image

news/191.feature

+For Windows users, `pdm --pep582` can enable PEP 582 globally by manipulating the WinReg.

pdm/cli/actions.py

@@ -14,6 +14,7 @@ from pdm.cli.utils import (
     format_lockfile,
     format_toml,
     save_version_specifiers,
+    set_env_in_reg,
 )
 from pdm.exceptions import NoPythonVersion, PdmUsageError, ProjectError
 from pdm.formats import FORMATS
@@ -540,18 +541,17 @@ def print_pep582_command(shell: str = "AUTO"):
     """Print the export PYTHONPATH line to be evaluated by the shell."""
     import shellingham
 
+    if os.name == "nt":
+        set_env_in_reg("PYTHONPATH", PEP582_PATH)
+        return
+    lib_path = PEP582_PATH.replace("'", "\\'")
     if shell == "AUTO":
         shell = shellingham.detect_shell()[0]
     shell = shell.lower()
-    lib_path = PEP582_PATH.replace("'", "\\'")
     if shell in ("zsh", "bash"):
         result = f"export PYTHONPATH='{lib_path}':$PYTHONPATH"
     elif shell == "fish":
         result = f"set -x PYTHONPATH '{lib_path}' $PYTHONPATH"
-    elif shell == "powershell":
-        result = f'$env:PYTHONPATH="{lib_path};$env:PYTHONPATH"'
-    elif shell == "cmd":
-        result = f"set PYTHONPATH={lib_path};%PYTHONPATH%"
     elif shell in ("tcsh", "csh"):
         result = f"setenv PYTHONPATH '{lib_path}':$PYTHONPATH"
     else:

pdm/cli/utils.py

 from __future__ import annotations
 
 import argparse
+import os
+import sys
 from collections import ChainMap
 from typing import TYPE_CHECKING, Optional
 
@@ -411,3 +413,36 @@ def find_importable_files(project: Project) -> Iterable[Tuple[str, Path]]:
         for key, module in FORMATS.items():
             if module.check_fingerprint(project, project_file.as_posix()):
                 yield key, project_file
+
+
+def set_env_in_reg(env_name: str, value: str) -> None:
+    """Manipulate the WinReg, and add value to the
+    environment variable if exists or create new.
+    """
+    import winreg
+
+    value = os.path.normcase(value)
+
+    with winreg.ConnectRegistry(None, winreg.HKEY_CURRENT_USER) as root:
+        with winreg.OpenKey(root, "Environment", 0, winreg.KEY_ALL_ACCESS) as env_key:
+            try:
+                old_value, type_ = winreg.QueryValueEx(env_key, env_name)
+            except FileNotFoundError:
+                old_value, type_ = "", winreg.REG_EXPAND_SZ
+            new_value = ";".join(old_value, value) if old_value else value
+            try:
+                winreg.SetValueEx(env_key, env_name, 0, type_, new_value)
+            except PermissionError:
+                stream.echo(
+                    stream.red(
+                        "Permission denied, please run the terminal as administrator."
+                    ),
+                    err=True,
+                )
+                sys.exit(1)
+    stream.echo(
+        stream.green(
+            "The environment variable has been saved, "
+            "please restart the session to take effect."
+        )
+    )